The wedding might have been a solution, an escape valve for the suffocating pressure of a stern cultural view imposed on Zainab Shafia by her father, with his unbending views of Afghan tradition. But it ended in disaster.

When the young woman’s husband arrived at the wedding reception without any members of his family, the Shafias considered it unforgivable. It sparked a startling threat from Zainab’s brother, Hamed. “Hamed said, if I leave with you,” she whispered to her new husband, “he’s going to kill everyone here and then he’s going to kill himself.”

The threat ended the party and, combined with so much other pressure, her one-day-old marriage.

That 2009 threat is part of a previously unreported layer of violence and control that was exerted by the men of the Shafia family over the female family members. Six weeks after Hamed delivered that chilling wedding-day threat, Zainab, 19, and…